The use of laser beam energy for printing and marking purposes has been limited because of the high costs associated with the manufacture and use of the beam scanning devices. Furthermore, the sensitivity of such devices to vibrations and mishandlings of the equipment by workers in the work areas of use have detracted from the wide spread use of such devices. Beam masking systems are used in some scanning devices. These suffer from the operational disadvantage that considerable energy is absorbed by the masks and hence are less than desirable because of the high energy costs associated with their use. They also require rather complex systems for handling the masks and which also contribute to excessive manufacturing costs. Other scanning devices utilize expensive galvanic deflection and/or other devices that are highly sensitive to vibrations and equipment mishandlings which commonly occur in the work area. Such devices are not only expensive to manufacture but obviously lack the ruggedness desired in many work applications.
A general object of the invention is to provide an improved laser beam scanning device. Another object is to provide improvements in laser beam scanning devices which facilitate the use of lower cost items in the manufacture of such devices, typical of such lower cost items being simple, inexpensive lenses that are readily available in the market area. Another object is to provide improvements that facilitate a compact arrangement of the components in the beam scanning device. Yet another object is to provide improvements that avoid the use of masks and galvanic deflectors in beam scanning devices that are used in laser marking systems. Yet another objective is to provide an improved laser beam scanning device that is especially suited for printing in a dot matrix format and which readily lends itself for use in laser marking systems of the type requiring but a few lines of alphanumeric information, such as found, for example, in systems used for labelling packages or marking metal parts for identification purposes.